Extraction of 2-acetyl-1-pyrroline from rice seeds by acidic aqueous solution has the advantage over the SDS technique that no heat is involved, so that, oxidations or Maillard reactions of some molecules are prevented. Other reactions of organic components which may result in formation or degradation of compounds, especially the target 2-acetyl-1-pyrroline, are also minimized. Furthermore, the relative concentration of 2-acetyl-1-pyrroline, a slightly basic compound, as well as other basic components, can be enhanced in acidic solution relative to those of non-basic components contained in rice. Thus, the rice seed extracts yield a less complex mixture of components than that obtained from the conventional simple steam distillation or SDS technique. Consequently, quantification of the aroma compound 2-acetyl-1-pyrroline by the use of an internal standard method is more efficient.